Method and device for producing melt-spun continuous threads

ABSTRACT

A method and device for producing melt-spun continuous threads includes two preparers spaced apart from one another, at each of which a partial quantity of a preparation is applied to the threads. A first preparation is performed upstream of a first draw-off device and a second downstream of the first draw-off device. As a result, high cohesion of the filaments in the thread is achieved.

BACKGROUND OF THE INVENTION

The invention relates to a method and device for producing melt-spuncontinuous threads.

In the production of melt-spun continuous threads, the problem existsthat the threads that are not further treated come apart as they aredrawn off and drafted on the galettes; that is, the individual filamentscome apart, and individual threads mix with one another. This has anadverse effect on the smooth travel of the thread, the maximum possiblecapacity of a galette, and in multicolor threads, the clarity of theindividual colors.

From European Patent Disclosure EP 0 485 871 B1, a method and a devicehave become known in which differently dyed partial threads, after apreparation, are individually precompacted, drafted individually ongalettes, and then jointly textured, compacted, and wound onto a bobbin;the precompacting is reversed again during the drafting. The goal of theprecompacting is said to be that the partial threads have a certaincohesion during processing, and the finished yarn has clearlydistinguishable colors.

In European Patent Disclosure EP 0 784 109 A2, a method and a device forcreating a multicolor yarn are described, in which differently dyedpartial threads or partial threads to be dyed differently are treated insuch a way that before a final compacting done jointly, the partialthreads are separated again, individually subjected to a furtherso-called postcompacting, then united, compacted and wound onto abobbin. Once again, the goal is to attain compactness of the partialthreads and different colors in the yarn.

The known methods have a number of disadvantages. Compacting is usuallydone by means of compressed air; this type of energy is very expensive,so that the production costs for the threads increase sharply with thenumber of compacting operations. A first compactor is disposedimmediately downstream of the preparer; the effect is that by thecompacting, some of the preparation agent is forced out of the threadand thus lost to the production process. Also, this portion of thepreparation agent is atomized because of the action of the compressedair; because this presents a health risk to workers and a risk to theenvironment, this mist must be caught and disposed of. Finally, theknots created by the compacting lead to nonhomogeneity and interferewith the drafting.

SUMMARY OF THE INVENTION

The invention is suitable for producing various yarn qualities, such asBCF (carpet fiber; textile fibers, industrial yarns) and FDY. Theprocess includes at least the steps of spinning and cooling thefilaments as well as preparation and drawing off of the filamentscombined into partial threads. Depending on the later use, such steds asdrafting, texturing, compacting, bobbin winding, and so forth are addedeither individually or in combination. In these remarks, “filament”describes a single fiber, while “thread” and “yarn” mean many filaments,joined together. A thread or yarn can be assembled from a plurality ofpartial threads that are processed separately before being joinedtogether.

The object of the invention is to disclose a method for producingmelt-spun continuous threads, in which with minimal use of aids such ascompressed air and preparation agent, optimal thread travel on thegalettes is attained with simultaneous high capacity, better performancein further handling steps such as drafting and texturing, and in thecase of multicolor threads, high color contrast. Another object is tocreate a device for performing the method of the invention.

The preparation of a thread is performed in at least two stations, whichare spaced apart from one another, in each case with a partial quantityof the total preparation agent required; the second preparer is disposeddownstream of the first draw-off device. The preparation agent that isapplied at a first station accordingly has enough time to penetrate farinto the thread and to be distributed in it; this process is reinforcedespecially at the deflection at the draw-off device, where the threadundergoes fulling. The second preparer has the effect that thepreparation agent overall can be applied maximally uniformly to theentire surface of all the filaments, without any substantial excess.This promotes the heat transfer between the thread and galettes as wellas the further processing, such as drafting. A thread maintains acompact shape without coming apart. As a result, it is possible for manythreads to be drawn over one galette, and/or to use a high wrap number,without requiring compacting. At the same time, very high thread speedsare possible. The risk of filament breakage is reduced.

Disposing the second preparer immediately upstream of the drafting hasthe advantage that an optimal heat transfer on the galettes can beachieved.

Limiting the quantity of preparation agent prevents losses andenvironmental impairment from ejection of the agent from the thread.

The preparation agents with an optimal effect for the subsequent methodsteps can be employed.

Claim 5 attains the second object.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings serve to explain the invention in terms of exemplaryembodiments shown in simplified, schematic form.

FIG. 1 shows a device for producing a melt-spun continuous thread.

FIG. 2 shows a variant of FIG. 1 for producing a multicolor yarn.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the device shown in FIG. 1, immediately under a nozzle plate 1 is aspinning chute 2, in which the filaments 3 leaving the nozzle plate 1are cooled. Many filaments 3 are combined into one thread 4 before beingfurther treated. A first preparer 5, which can be assembled from aplurality of preparation stations 5.10, 5.20 disposed immediately oneafter the other, is disposed downstream of the spinning chute 2. Theprepared thread 4 wraps multiple times, such as from 1.5 to 2 times,around a drivable galette 6 and a deflection roller 7. The galette 6 anddeflection roller 7 form the first draw-off device. Between the galette6 and a first pair 8 of galettes, a second preparer 9 is provided. Thepair 8 of galettes comprises two vertically spaced-apart galettes 8.1,8.2, which can each be driven and heated, and the thread 4 wraps aroundthem multiple times, for instance from 5 to 13 times. Downstream of itis a second pair 10 of galettes, and once again the thread 4 wrapsaround them multiple times. The associated galettes 10.1, 10.2 are eachdrivable and are spaced apart both horizontally and vertically.Downstream of the galette 10.1 is a texturer 11, followed by a drivablecooling roller 12. Downstream of the cooling roller 12, the thread 4passes via a drivable galette 13 and a deflection roller 14 to reach thecompactor 15. The thread 4 is then guided over the drivable galette 16and the deflection roller 17 to the bobbin winder 18. The entire device,beginning with the first preparer 5 but without the bobbin winder 18, isexpediently mounted on a frame 19.

In operation, molten plastic is forced through the nozzle plate 1 andspun into filaments 3. The filaments are cooled in the spinning chute 2,for instance by a stream of air, so that the plastic of the filaments 3solidifies. The filaments 3 combined into a thread 4 are moistened withpreparation agent in the first preparer 5; the quantity of preparationagent is about 75% of the total quantity required, for instance. Thepreparation agent has the effect that during further processing, thethread 4 is maximally compact, and that a good heat transfer is attainedbetween the thread and the galette, for instance. The thread 4 is drawnoff via the galette 6 and the deflector 7 and delivered to the secondpreparer 9. Since the preparation agent that was applied in the firstpreparer 5 was able to penetrate far into the thread 4, it is nowpossible for the missing quantity of preparation agent for optimalfurther processing to be applied without requiring any significantexcess. It is also possible to use a second preparation agent. Thethread is then drafted in a known manner by the pairs 8, 10 of galettes,crimped in the texturer 11, cooled on the cooling roller 12, tangled inthe compactor 15, and finally wound onto bobbins by means of the bobbinwinding machines 18. The galettes 13, 16 with the deflection rollers 14,17 each serve to draw off the thread 4.

Depending on the intended purpose of the thread 4, the device can besupplemented with further devices or shortened by some treatment steps.

For producing a multicolor yarn, FIG. 2 shows a device for three colorsas an example. The filaments 3.1, 3.2, 3.3, dyed differently or to bedyed differently, each travel, after emerging from the spinneret 1.1,1.2, 1.3, directly into a spinning chute 2.1, 2.2, 2.3 and are thenjoined into three individual threads 4.1, 4.2, 4.3, respectively. Eachindividual thread 4.1, 4.2, 4.3 is assigned a first preparer 5.1, 5.2,5.3 below the spinning chute 2.1, 2.2, 2.3. The first preparer 5.1, 5.2,5.3 can be assembled from a plurality of preparation stationsimmediately in line with one another. The further layout of the deviceis as in the description of FIG. 1, with the exception that for eachindividual thread 4.1, 4.2, 4.3, a separate second preparer 9.1, 9.2,9.3 is provided.

The mode of operation is essentially in accordance with the abovedescriptions. The various threads 4.1, 4.2, 4.3 dyed differently or tobe dyed differently are kept separate until before the texturer 11, sothat a separate treatment takes place in each case. This is assured onthe one hand by a suitable thread guidance and on the other by thecompactness of a thread 4.1, 4.2, 4.3 as a consequence of thepreparation. The threads 4.1, 4.2, 4.3 are then, as described above,preferably jointly textured, cooled, compacted and wound onto bobbins.

The devices shown as examples in FIGS. 1 and 2 can also be embodied suchthat a plurality of threads, for instance two, four, six or eightthreads, can be processed simultaneously and in parallel.

List of Reference Numerals

1. Nozzle plate

2. Spinning chute

3. Filament

4. Thread

5. First preparer

6. Galette

7. Deflection roller

8. Pair of galettes

9. Second preparer

10. Pair of galettes

11. Texturer

12. Cooling roller

13. Galette

14. Deflection roller

15. Compactor

16. Galette

17. Deflection roller

18. Bobbin winder

19. Frame

What is claimed is:
 1. A method for producing melt-spun, continuous,multi-color threads from a plurality of filaments, wherein differentlydyed or dyeable filaments are combined in groups of at least two threadsand are drawn off, the method comprising at least the following steps:performing first a preparation of the threads with a preparation agentat least before a first draw-off device; stretching the threads;texturing the threads, wherein the threads are crimped; cooling thethreads; compacting the threads without precompaction after the firstpreparation; and winding the threads, wherein at least a secondpreparation is performed after the first draw-off device and before thestretching.
 2. The method of claim 1, wherein the filaments are heldseparately inclusive of the stretching, then are combined as thread andcommonly textured, cooled, compacted, and wound.
 3. The method of claim1, wherein in the first preparation, precisely enough preparation agentis applied that good travel on the first draw-off device is assured. 4.The method of claim 1, wherein in the first preparation and the secondpreparation, different preparation agents are employed.
 5. A device forproducing melt-spun, continuous, multi-color threads from a plurality offilaments, wherein differently colored or colorable filaments arecombined in groups of at least two threads, comprising: a draw-offdevice, comprising a galette and a deflection roller; a first preparerarranged before the draw-off device; first and second galette pairs,wherein the threads are stretched between the galette pairs; a texturingdevice; a cooling roller; a compacting device arranged without aprecompacting device after the first preparer; and a winding device,wherein a second preparer is arranged between the draw-off device andthe first galette pair.
 6. The device of claim 5, wherein the eachthread is separately arranged.
 7. The device of claim 5, wherein thefirst preparer can comprise two immediately adjacent preparationstations.